Journal of Rock Mechanics and Geotechnical Engineering最新文献

{"title":"A review of rock macro-indentation: Theories, experiments, simulations, and applications","authors":"Weiqiang Xie, Xiaoli Liu, Xiaoping Zhang, Xinmei Yang, Xiaoxiong Zhou","doi":"10.1016/j.jrmge.2023.07.022","DOIUrl":"https://doi.org/10.1016/j.jrmge.2023.07.022","url":null,"abstract":"Rock macro-indentation plays a fundamental role in mechanical rock breaking for various rock engineering application, such as drilling, tunneling, cutting, and sawing. Over the past decades, extensive research has been conducted to understand the indentation mechanisms and responses through various approaches. This review aims to provide an overview of the current status and recent advancements in theories, experiments, numerical simulations, and applications of macro-indentation in rock engineering. It starts with elaborating on the mechanisms of macro-indentation, followed by a discussion of the merits and limitations of commonly used models. Influence factors and their effects on indentation test results are then summarized. Various numerical simulation methods for rock macro-indentation are highlighted, along with their advantages and disadvantages. Subsequently, the applications of indentation tests and indentation indices in characterizing rock properties are explored. It reveals that compression-tension, compression-shear, and composite models are widely employed in rock macro-indentation. While the compression-tension model is straightforward to use, it may overlook the anisotropic properties of rocks. On the other hand, the composite model provides a more comprehensive description of rock indentation but requires complex calculations. Additionally, factors, such as indentation rate, indenter geometry, rock type, specimen size, and confining pressure, can significantly influence the indentation results. Simulation methods for macro-indentation encompass continuous medium, discontinuous medium, and continuous-discontinuous medium methods, with selection based on their differences in principle. Furthermore, rock macro-indentation can be practically applied to mining engineering, tunneling engineering, and petroleum drilling engineering. Indentation indices serve as valuable tools for characterizing rock strength, brittleness, and drillability. This review sheds light on the development of rock macro-indentation and its extensive application in engineering practice. Specialists in the field can gain a comprehensive understanding of the indentation process and its potential in various rock engineering endeavors.","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135670397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A coupled thermo-mechanical peridynamic model for fracture behavior of granite subjected to heating and water-cooling processes","authors":"Luming Zhou, Zhende Zhu","doi":"10.1016/j.jrmge.2023.07.021","DOIUrl":"https://doi.org/10.1016/j.jrmge.2023.07.021","url":null,"abstract":"Thermal damage and thermal fracture of rocks are two important indicators in geothermal mining projects. This paper investigates the effects of heating and water-cooling on granite specimens at various temperatures. The laboratory uniaxial compression experiments were also conducted. Then, a coupled thermo-mechanical ordinary state-based peridynamic (OSB-PD) model and corresponding numerical scheme were developed to simulate the damage of rocks after the heating and cooling processes, and the change of crack evolution process was predicted. The results demonstrate that elevated heating temperatures exacerbate the thermal damage to the specimens, resulting in a decrease in peak strength and an increase in ductility of granite. The escalating occurrence of thermal-induced cracks significantly affects the crack evolution process during the loading phase. The numerical results accurately reproduce the damage and fracture characteristics of the granite under different final heating temperatures (FHTs), which are consistent with the test results in terms of strength, crack evolution process, and failure mode.","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"45 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135564427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Three-dimensional finite element simulation and reconstruction of jointed rock models using CT scanning and photogrammetry","authors":"Yingxian Lang, Zhengzhao Liang, Zhuo Dong","doi":"10.1016/j.jrmge.2023.08.008","DOIUrl":"https://doi.org/10.1016/j.jrmge.2023.08.008","url":null,"abstract":"The geometry of joints has a significant influence on the mechanical properties of rocks. To simplify the curved joint shapes in rocks, the joint shape is usually treated as straight lines or planes in most laboratory experiments and numerical simulations. In this study, the computerized tomography (CT) scanning and photogrammetry were employed to obtain the internal and surface joint structures of a limestone sample, respectively. To describe the joint geometry, the edge detection algorithms and a three-dimensional (3D) matrix mapping method were applied to reconstruct CT-based and photogrammetry-based jointed rock models. For comparison tests, the numerical uniaxial compression tests were conducted on an intact rock sample and a sample with a joint simplified to a plane using the parallel computing method. The results indicate that the mechanical characteristics and failure process of jointed rocks are significantly affected by the geometry of joints. The presence of joints reduces the uniaxial compressive strength (UCS), elastic modulus, and released acoustic emission (AE) energy of rocks by 37%–67%, 21%–24%, and 52%–90%, respectively. Compared to the simplified joint sample, the proposed photogrammetry-based numerical model makes the most of the limited geometry information of joints. The UCS, accumulative released AE energy, and elastic modulus of the photogrammetry-based sample were found to be very close to those of the CT-based sample. The UCS value of the simplified joint sample (i.e. 38.5 MPa) is much lower than that of the CT-based sample (i.e. 72.3 MPa). Additionally, the accumulative released AE energy observed in the simplified joint sample is 3.899 times lower than that observed in the CT-based sample. CT scanning provides a reliable means to visualize the joints in rocks, which can be used to verify the reliability of photogrammetry techniques. The application of the photogrammetry-based sample enables detailed analysis for estimating the mechanical properties of jointed rocks.","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"106 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135514910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Permeability evolution mechanism and the optimum permeability determination of uranium leaching from low-permeability sandstone treated with low-frequency vibration","authors":"Yong Zhao ,&nbsp;Xiqi Li ,&nbsp;Lin Lei ,&nbsp;Ling Chen ,&nbsp;Zhiping Luo","doi":"10.1016/j.jrmge.2022.12.031","DOIUrl":"10.1016/j.jrmge.2022.12.031","url":null,"abstract":"<div><p>Low-frequency vibrations can effectively improve natural sandstone permeability, and higher vibration frequency is associated with larger permeability. However, the optimum permeability and permeability evolution mechanism for uranium leaching and the relationship between permeability and the change of chemical reactive rate affecting uranium leaching have not been determined. To solve the above problems, in this study, identical homogeneous sandstone samples were selected to simulate low-permeability sandstone; a permeability evolution model considering the combined action of vibration stress, pore water pressure, water flow impact force, and chemical erosion was established; and vibration leaching experiments were performed to test the model accuracy. Both the permeability and chemical reactions were found to simultaneously restrict U⁶⁺ leaching, and the vibration treatment increased the permeability, causing the U⁶⁺ leaching reaction to no longer be diffusion-constrained but to be primarily controlled by the reaction rate. Changes of the model calculation parameters were further analyzed to determine the permeability evolution mechanism under the influence of vibration and chemical erosion, to prove the correctness of the mechanism according to the experimental results, and to develop a new method for determining the optimum permeability in uranium leaching. The uranium leaching was found to primarily follow a process consisting of (1) a permeability control stage, (2) achieving the optimum permeability, (3) a chemical reactive rate control stage, and (4) a channel flow stage. The resolution of these problems is of great significance for facilitating the application and promotion of low-frequency vibration in the CO₂ + O₂ leaching process.</p></div>","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"15 10","pages":"Pages 2597-2610"},"PeriodicalIF":7.3,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48187151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Displacement-based back analysis of mitigating the effects of displacement loss in underground engineering","authors":"Hui Li,&nbsp;Weizhong Chen,&nbsp;Xianjun Tan","doi":"10.1016/j.jrmge.2022.12.036","DOIUrl":"10.1016/j.jrmge.2022.12.036","url":null,"abstract":"<div><p>Displacement-monitoring-based back analysis is a popular method for geomechanical parameter estimation. However, due to the delayed installation of multi-point extensometers, the monitoring curve is only a part of the overall one, leading to displacement loss. Besides, the monitoring and construction time on the monitoring curve is difficult to determine. In the literature, the final displacement was selected for the back analysis, which could induce unreliable results. In this paper, a displacement-based back analysis method to mitigate the influence of displacement loss is developed. A robust hybrid optimization algorithm is proposed as a substitute for time-consuming numerical simulation. It integrates the strengths of the nonlinear mapping and prediction capability of the support vector machine (SVM) algorithm, the global searching and optimization characteristics of the optimized particle swarm optimization (OPSO) algorithm, and the nonlinear numerical simulation capability of ABAQUS. To avoid being trapped in the local optimum and to improve the efficiency of optimization, the standard PSO algorithm is improved and is compared with other three algorithms (genetic algorithm (GA), simulated annealing (SA), and standard PSO). The results indicate the superiority of OPSO algorithm. Finally, the hybrid optimization algorithm is applied to an engineering project. The back-analyzed parameters are submitted to numerical analysis, and comparison between the calculated and monitoring displacement curve shows that this hybrid algorithm can offer a reasonable reference for geomechanical parameters estimation.</p></div>","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"15 10","pages":"Pages 2626-2638"},"PeriodicalIF":7.3,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49272148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of rockburst mechanism and warning based on microseismic moment tensors and dynamic Bayesian networks","authors":"Haoyu Mao ,&nbsp;Nuwen Xu ,&nbsp;Xiang Li ,&nbsp;Biao Li ,&nbsp;Peiwei Xiao ,&nbsp;Yonghong Li ,&nbsp;Peng Li","doi":"10.1016/j.jrmge.2022.12.005","DOIUrl":"10.1016/j.jrmge.2022.12.005","url":null,"abstract":"<div><p>One of the major factors inhibiting the construction of deep underground projects is the risk posed by rockbursts. A study was conducted on the access tunnel of the Shuangjiangkou hydropower station to determine the evolutionary mechanism of microfractures within the surrounding rock mass during rockburst development and develop a rockburst warning model. The study area was chosen through the combination of field studies with an analysis of the spatial and temporal distribution of microseismic (MS) events. The moment tensor inversion method was adopted to study rockburst mechanism, and a dynamic Bayesian network (DBN) was applied to investigating the sensitivity of MS source parameters for rockburst warnings. A MS multivariable rockburst warning model was proposed and validated using two case studies. The results indicate that fractures in the surrounding rock mass during the development of strain-structure rockbursts initially show shear failure and are then followed by tensile failure. The effectiveness of the DBN-based rockburst warning model was demonstrated using self-validation and <em>K</em>-fold cross-validation. Moment magnitude and source radius are the most sensitive factors based on an investigation of the influence on the parent and child nodes in the model, which can serve as important standards for rockburst warnings. The proposed rockburst warning model was found to be effective when applied to two actual projects.</p></div>","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"15 10","pages":"Pages 2521-2538"},"PeriodicalIF":7.3,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43114799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Shear sliding of rough-walled fracture surfaces under unloading normal stress","authors":"Qian Yin ,&nbsp;Chun Zhu ,&nbsp;Jiangyu Wu ,&nbsp;Hai Pu ,&nbsp;Qi Wang ,&nbsp;Yuanchao Zhang ,&nbsp;Hongwen Jing ,&nbsp;Tianci Deng","doi":"10.1016/j.jrmge.2023.02.005","DOIUrl":"10.1016/j.jrmge.2023.02.005","url":null,"abstract":"<div><p>Through high-precision engraving, self-affine sandstone joint surfaces with various joint roughness coefficients (<em>JRC</em> = 3.21–12.16) were replicated and the shear sliding tests under unloading normal stress were conducted regarding various initial normal stresses (1–7 MPa) and numbers of shearing cycles (1–5). The peak shear stress of fractures decreased with shear cycles due to progressively smooth surface morphologies, while increased with both JRC and initial normal stress and could be verified using the nonlinear Barton-Bandis failure criterion. The joint friction angle of fractures exponentially increased by 62.22%–64.87% with JRC while decreased by 22.1%–24.85% with shearing cycles. After unloading normal stress, the sliding initiation time of fractures increased with both JRC and initial normal stress due to more tortuous fracture morphologies and enhanced shearing resistance capacity. The surface resistance index (SRI) of fractures decreased by 4.35%–32.02% with increasing shearing cycles due to a more significant reduction of sliding initiation shear stress than that for sliding initiation normal stress, but increased by a factor of 0.41–1.64 with JRC. After sliding initiation, the shear displacement of fractures showed an increase in power function. By defining a sliding rate threshold of 5 × 10⁻⁵ m/s, transition from “quasi-static” to “dynamic” sliding of fractures was identified, and the increase of sliding acceleration steepened with JRC while slowed down with shearing cycles. The normal displacement experienced a slight increase before shear sliding due to deformation recovery as the unloading stress was unloaded, and then enhanced shear dilation after sliding initiation due to climbing effects of surface asperities. Dilation was positively related to the shear sliding velocity of fractures. Wear characteristics of the fracture surfaces after shearing failure were evaluated using binary calculation, indicating an increasing shear area ratio by 45.24%–91.02% with normal stress.</p></div>","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"15 10","pages":"Pages 2658-2675"},"PeriodicalIF":7.3,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43929407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of thawing-induced softening on fracture behaviors of frozen rock","authors":"Ting Wang, Hailiang Jia, Qiang Sun, Xianjun Tan, Liyun Tang","doi":"10.1016/j.jrmge.2023.07.016","DOIUrl":"https://doi.org/10.1016/j.jrmge.2023.07.016","url":null,"abstract":"Due to the presence of ice and unfrozen water in pores of frozen rock, the rock fracture behaviors are susceptible to temperature In this study, the potential thawing-induced softening effects on the fracture behaviors of frozen rock is evaluated by testing the tension fracture toughness (KIC) of frozen rock at different temperatures (i.e. −20 °C, −15 °C, −12 °C, −10 °C, −8 °C, −6 °C, −4 °C, −2 °C, and 0 °C). Acoustic emission (AE) and digital image correlation (DIC) methods are utilized to analyze the microcrack propagation during fracturing. The melting of pore ice is measured using nuclear magnetic resonance (NMR) method. The results indicate that: (1) The KIC of frozen rock decreases moderately between −20 °C and −4 °C, and rapidly between −4 °C and 0 °C. (2) At −20 °C to −4 °C, the fracturing process, deduced from the DIC results at the notch tip, exhibits three stages: elastic deformation, microcrack propagation and microcrack coalescence. However, at −4 °C–0 °C, only the latter two stages are observed. (3) At −4 °C–0 °C, the AE activities during fracturing are less than that at −20 °C to −4 °C, while more small events are reported. (4) The NMR results demonstrate a reverse variation trend in pore ice content with increasing temperature, that is, a moderate decrease is followed by a sharp decrease and −4 °C is exactly the critical temperature. Next, we interpret the thawing-induced softening effect by linking the evolution in microscopic structure of frozen rock with its macroscopic fracture behaviors as follow: from −20 °C to −4 °C, the thickening of the unfrozen water film diminishes the cementation strength between ice and rock skeleton, leading to the decrease in fracture parameters. From −4 °C to 0 °C, the cementation effect of ice almost vanishes, and the filling effect of pore ice is reduced significantly, which facilitates microcrack propagation and thus the easier fracture of frozen rocks.","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134936111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical and experimental analyses of rock failure mechanisms due to microwave treatment","authors":"Haitham M. Ahmed ,&nbsp;Adel Ahmadihosseini ,&nbsp;Ferri Hassani ,&nbsp;Mohammed A. Hefni ,&nbsp;HussinA.M. Ahmed ,&nbsp;Hussein A. Saleem ,&nbsp;Essam B. Moustafa ,&nbsp;Agus P. Sasmito","doi":"10.1016/j.jrmge.2023.02.016","DOIUrl":"10.1016/j.jrmge.2023.02.016","url":null,"abstract":"<div><p>Despite the extensive studies conducted on the effectiveness of microwave treatment as a novel rock pre-conditioning method, there is yet to find reliable data on the rock failure mechanisms due to microwave heating. In addition, there is no significant discussion on the energy efficiency of the method as one of the important factors among the mining and geotechnical engineers in the industry. This study presents a novel experimental method to evaluate two main rock failure mechanisms due to microwave treatment without applying any mechanical forces, i.e. distributed and concentrated heating. The result shows that the existence of a small and concentrated fraction of a strong microwave absorbing mineral will change the failure mechanism from the distributed heating to the concentrated heating, which can increase the weakening over microwave efficiency (WOME) by more than 10 folds. This observation is further investigated using the developed coupled numerical model. It is shown that at the same input energy, the existence of microwave absorbing minerals can cause major heat concentration inside the rock and increase the maximum temperature by up to three times.</p></div>","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"15 10","pages":"Pages 2483-2495"},"PeriodicalIF":7.3,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42845566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic mechanical characteristics of deep Jinping marble in complex stress environments","authors":"Chendi Lou, Heping Xie, Ru Zhang, Hai Ren, Hao Luo, Kun Xiao, Yuan Peng, Qiang Tan, Li Ren","doi":"10.1016/j.jrmge.2023.08.005","DOIUrl":"https://doi.org/10.1016/j.jrmge.2023.08.005","url":null,"abstract":"To reveal the dynamic mechanical characteristics of deep rocks, a series of impact tests under triaxial static stress states corresponding to depths of 300–2400 m were conducted. The results showed that both the strain rates and the stress environments in depth significantly affect the mechanical characteristics of rocks. The sensitivity of strain rate to the dynamic strength and deformation modulus shows a negative correlation with depth, indicating that producing penetrative cracks in deep environments is more difficult when damage occurs. The dynamic strength shows a tendency to decrease and then increase slightly, but decreases sharply finally. Transmissivity demonstrates a similar trend as that of strength, whereas reflectivity indicates the opposite trend. Furthermore, two critical depths with high dynamically induced hazard possibilities based on the China Jinping Underground Laboratory (CJPL) were proposed for deep engineering. The first critical depth is 600–900 m, beyond which the sensitivity of rock dynamic characteristics to the strain rate and restraint of circumferential stress decrease, causing instability of surrounding rocks under axial stress condition. The second one lies at 1500–1800 m, where the wave impedance and dynamic strength of deep surrounding rocks drop sharply, and the dissipation energy presents a negative value. It suggests that the dynamic instability of deep surrounding rocks can be divided into dynamic load dominant and dynamic load induced types, depending on the second critical depth.","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"189 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135761844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}